1. Field of the Invention
The present invention relates to a microfilm reader/printer, and more particularly to a microfilm reader/printer which displays by projection the image information that is recorded in the microfilm on a screen, or prints the information on a recording paper or the like.
2. Description of the Prior Art
Microfilm has been used widely hitherto for recording and keeping various kinds of information. Since microfilm records information as image information reduced in size, there is provided a device, namely, a microfilm reader/printer which optically projects the reduced image information that is recorded in the microfilm on the screen to display it enlarged, and print the information on a recording paper as need arises.
Now, there are two kinds of images recorded in a microfilm, namely, a positively recorded image and a negatively recorded image. Accordingly, in printing out these two kinds of microfilms, there are two cases of printing, that is, printing out a positively recorded image as a positively printed image and printing out a negatively recorded image as printed image. Generally speaking, there are more of the negatively recorded image type of microfilms such that the printing mode of printing a negatively recorded image into a positively printed image is automatically set as the priority mode for the microfilm reader/printer. Thus, if an operator who has been using the machine in another printing mode, for instance, printing out a microfilm which is recorded in positive images into positive images, interrupts the printing operation for a relatively short time, the machine returns automatically to the priority mode mentioned above. As a result, if the operator resumes the printing operation without noticing this change, the machine performs printing according to the priority mode which is a mode that is different from what he has been doing earlier intermittently resulting in a misprint.
Further, in the printing operation, the number of prints desired is set by the previous operator. The number of prints thus set is memorized, for instance, in the memory register, and in the prior-art device, it is arranged that the number of desired prints set by the previous operator is saved in the memory register at the completion of the printing operation. For this reason, with a shift in the operator, if the next operator carries out the printing operation with neither confirming nor clearing the number of prints set by the previous operator, the machine will proceed to print out according to the desired number of prints as set by the previous operator. This may lead sometimes to printing of more than what is needed, which leads to the waste of recording papers, toner, and other materials.
Moreover, the main power supply to the microfilm reader/printer is ordinarily turned off for energy saving reasons when the machine is not in use. However, when the main power source is turned off, the device is turned off as a whole so that the heater lamp for fixing the developed image of the image information on the recording paper is either turned off or at a temperature which is below the fixing temperature. Consequently, the machine cannot be used again until the heater lamp attains the fixing temperature, which is very inconvenient.
Now, to obtain the projection light for the microfilm, it is necessary to provide a lamp for the light source. If the main power supply is kept in the state of turned on in the prior-art microfilm reader/printer, in order to eliminate the above-mentioned inconvenience, the light source lamp is kept in the state of lighting, so that the life of the light source lamp is shortened and a wasteful consumption of power is also generated. In addition, a large amount of power is also required to keep the heater lamp at the fixing temperature.